Adjustable clamp for light shields



April 10, 1951 R. J. BRANDT 2,548,650

ADJUSTABLE CLAMP FOR LIGHT SHIELDS Filed Oct. 2, 1946 I N V EN TOR.

Patented Apr. 10, 1951 UNITED STATES PATENT OFFICE 2,548,650 ADJUSTABLECLAMP FOR LIGHT SHIELDS Robert J. Brandt, Los Angeles, Calif.

Application October 2, 1946, Serial No. 700,782

2 Claims. (01. 287 14) The invention relates to an adjustable clamp forlight shields for spot lamps or other lamps employed for photographicpurposes. In order to mask the light on a part of a set or scene beingphotographed, a gobo or flag in the form of a sheet of metal paintedblack is interposed in the path of the light. In order. to readilyadjust its position, the gobo or flag is mounted on a standard havinguniversal brackets so that the flag rod or pipe can be extended orretracted and revolved about various axes. A similar type of support isemployed for a cut-out or silhouette employed for casting a desiredshadow effect.

The adjustable brackets heretofore employed have a number of operatingparts and are of such a nature that the pipe or red can not very readilybe inserted into the bracket, and the pipe or rod is not clamped withsufficient rigidity.

An object of the present invention is to overcome the above defects andprovide a clamp having clamping members each ofwhich can be cast in onepiece in green sand without the use of cores, and more particularly tocast an attaching device on one of the clamp members so it can beattached to an adjustable support. The adjustment of the support and theoperation of the clamp are thus independent of each other.

Another object is to provide the clamp member which is fixed to theadjustable support, with a continuous circular rough surface andcooperating clamping member with a pipe or rod receiving groove, wherebythe groove clamping member can be rotated throughout a full circle toadjust the flag in any angular position throughout a full 360. Thegroove may be a comparatively large size to receive an adjustable pipestandard, the clamping members in this case being designated as a headclamp, and the groove in another casting may be made smaller to receivethe rod connected to the flag or silhouette, the clamp in this casebeing designated a small head clamp.

For further details of the invention reference may be made to thedrawings wherein Fig. 1 is a view in elevation of both the large andsmall head clamps according to the present invention.

Fig. 2 is an enlarged side view in elevation of the large head clamp ofFig. 1 for clamping a pipe.

Fig. 3 is an enlarged rear view in elevation looking toward the left inFig. 2, the pipes and standards in Figs. 2 and 3 being broken away.

Figs. 4 and 5 are perspective views of the two members which form theclamp.

Fig. 6 is a side view of a casting having a groove made by drilling andremoving the face of the casting.

Referring in detail to the drawings, the flag I has secured thereto arod 2 adjustably held in a small head clamp 3 having the clamp memberslike II and I6 of this invention. The flag I can be rotated around theaxis of the rod 2, also run 2 may be adjusted at various lengths in theclamp 3 and rod 2 may be angularly adjusted about an axis through thecenter 4 at right angles to the drawing. Clamp 3 is mounted on a pipe 5which may be rotated around its own axis in the large head clamp 6. Alsopipe 5 may be adjusted to various lengths extending from the clamp 6 andpipe ,5. may be angularly adjusted about a center 1 in the plane of thedrawings. Head clamp 6 is mounted on a vertical pipe 8 which can beadjusted to various heights in the standard 9 by means of a clamp Ill.

The clamps 3 and 6 have a clamp member H according to the presentinvention, as shown in Fig. 4, the only difference between the two beingin the size of the groove l2 which is of'a proper size for the rod 2 inthe one case, or for pipe 5 in the other case. The clamp member II has aclamp face [3 which lies in one plane and the groove l2 opens into thatface at one side of bore l4 and extends from one side of the disc shapedcasting to the other. Clamp member H has an axial bore [A somewhatlarger than the clamping bolt I5.

The cooperating clamping member I6 has a central threaded aperture llfor the bolt [5 which has a handle 26. 'Clamping member I6 has anannular knurled face 18 which is a complete annulus and it overlies thegroove l2 regardless of how the member II is rotated on the bolt 15.Clamp member I6 is also a casting and integral with it and at rightangles to its axis behind face 58 is a stub 19 which fits inside of andis brazed to its supporting pipe, namely 8 in the case of the large headclamp as shown in Fig. 2, or the stub 19 is brazed in the end of pipe 5if the device is used as a small head clamp 3.

As shown in Fig. 2, the groove I2 is semicylindrical at its lowerportion as shown at 20, t0 fit the pipe 5, while its outer portion hassides indicated at 30 and 3! which flare outwardly. Also, to reduce theweight of the casting 6, hollow portions 2|, 22 have outwardly flaringsides as shown in Fig. 4 whereby the member 6 may be cast in green sand,the groove 12 and the hollow portions 2|, 22 permitting the draft of themold, without the use of cores. Also the outwardly flaring sides 30 and3| result in the groove l2 having ends 23, 24 which readily permit theinsertion of the rod or pipe endwise into groove l2.

The depth of groove [2 is less than the diameter of its rod or pipe.When the rod or pipe is clamped in position, one side of the member 6rests on the adjacent side of the face I 8 as indicated at 25 in Fig. 2,while the other side of member 6 rests in the example shown, on pipe 5,member 6 being in a tilted position shown in Fig. 2. The bore I4 islarge enough to permit this tilt.

According to the modification shown in Fig. 6, the groove 21 for the rodor pipe may be formed by drilling the hole 21 in the head clamp 28 at atime when the right hand side 29 of the casting extends at some distanceto the right beyond that shown. The casting is then put in a lathe andthe face 29 is turned down until it cuts through one side of groove 21as shown, so that the rod or pipe will project beyond the face 29, adistance sufiicient to be engaged by the other clamp member shown inFig. 5.

Tests of the form shown Figs. 1 to have shown that the rod or pipe isvery rigidly clamped in position with the clamp of this invention, andthat the rod or pipe may be more readily inserted into theends of theclamp l2 than heretofore. Also the rotating adjustment of the flagsabout a vertical axis and its height may be adjusted by operating clampIn without disturbing the clamps 3, and 6. Also either clamp 3 or 6 maybe adjusted without disturbing the other clamp 6 or 3, or the clamp H3.

Various modifications may be made in the invention without departingfrom the spirit of the following claims.

I claim:

1. A clamp comprising a clamping member having a clamping face having aU-shaped groove extending across said face at one side thereof, saidgroove forming a seat for a rod or pipe and being of less depth than thediameter of the rod or pipe, a cooperating clamping member having acontinuous annular rough face extending completely around said lastmentioned clamping member and overlying said groove in position to gripthe rod or pipe in said groove, an elongated supporting member havingone end thereof integral with said last mentioned clamping member, aclamping bolt for said clamping members,- said cooperating clampingmember having a threaded bore for said bolt, said cooperating clampingmember having a stub behind said rough face, said stub extending substantially at a right angle to said threaded bore, said supportingmember comprising a pipe fitting over said stub and secured thereto, andan independent adjustable support for said supporting member.

2. A clamp comprising a clamping member having a clamping face having aU-shaped groove extending across said face at one side thereof, saidgroove forming a seat for a rod or pipe and being of less depth than thediameter of the rod or pipe, a cooperating clamping member having anannular rough face extending around said last mentioned clamping memberand overlying said groove in position to grip the rod or pipe in saidgroove, said clamping member having a central bore at one side of saidgroove and said cooperating clamping member having a threaded borecoaxial with said annular rough face, a clamping bolt for said bores,said cooperating clamping member having a stub behind said rough face,said stub extending substantially at a right angle to said threadedbore, and a supporting member comprising a pipe fitting over said stuband secured thereto.

ROBERT J. BRANDT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS France June 13, 1938

